In general, a silver halide color photographic material employs the three color separation process. Each silver halide layer is subjected to spectral sensitization with respective sensitizing dye. A blue-sensitive silver halide emulsion layer contains a yellow color coupler, a green-sensitive silver halide emulsion layer contains a magenta color coupler, and a red-sensitive silver halide emulsion layer contains a cyan color coupler. After being imagewise exposed to light, the light-sensitive material is processed with a color developing solution containing a p-phenylenediamine derivative as a color developing agent, and then subjected to blix to provide a color image. In order to improve the color reproduction of such a color image, it is very important to prevent the sensitivity of each silver halide emulsion layer from being affected by heat or moisture upon the imagewise exposure to light. On the other hand, studies have been made on irradiation dyes, anti-irradiation dyes, supports, and layer construction to improve the sharpness of the color image. In particular, dyes, which exert a great effect on the sharpness, have been intensively studied.
In order to select dyes suitably, some characteristics such as spectral absorption and decolorization and elution properties upon development were used as measures. Oxonol dyes, azo dyes, and anthraquinone dyes have been studied in the hope that they can satisfy these requirements. Excellent among these dyes are oxonol dyes. Examples of such dyes are disclosed in Japanese Patent Publication Nos. 13168/68, 1419/76, 28085/78, 10060/80, 10061/80, 10187/80 and 10899/80, Japanese Patent Application (OPI) Nos. 145125/75 and 33104/80 (the term "OPI" as used herein means an unexamined published patent application), U.S. Pat. No. 3,647,460, and British Patent No. 1,338,799.
In the silver halide color photographic material, if the crystalline phases of the silver halide emulsion are uniformed so that a monodispersion is provided, the density of the color image can be increased, making it possible to save the amount of silver to be coated. Furthermore, if a combination of one or more silver halide emulsions is used, an excellent gradation can be obtained, improving the color reproduction. However, a silver halide emulsion containing many (100) faces has some disadvantages. While such a silver halide emulsion can easily adsorb a spectral sensitizer, maintaining a suitable spectral sensitivity for color reproduction, and shows a small change in the sensitivity during the storage of unprocessed photographic materials for a long period of time, it causes a sensitivity drop due to effects other than optical absorption effect if the above mentioned dyes are used, and further causes a bigger sensitivity drop if the humidity upon exposure becomes high. Such a sensitivity drop greatly impedes the color reproduction. On the other hand, in order to improve the sharpness of the color image, it is desired that the maximum spectral absorption of the dye is consistent with that of each silver halide emulsion layer. However, the oxonol dyes which provide an improved spectral sensitivity still cause a sensitivity drop.
Oxonol dyes excellent in decolorization and elution properties upon development are disclosed in Japanese Patent Publication Nos. 22069/64, 3504/68, 46607/76 and 10059/80, Japanese Patent Application (OPI) No. 225155/85, and U.S. Pat. No. 4,564,590. However, there are no reference to important characteristics of sensitivity for color reproduction. Furthermore, the characteristics of silver halide emulsions to be combined are not made clear.